Septa N 20, Butyl/PTFE (Pharma-Fix), Dark gray/gray, 3.0 mm, 50° shore A
*taxes and shipping not included
Delivery time approx. 5 working days
Quantity | Price/unit |
---|---|
To 9 | $59.80 |
From 10 | $50.90 |
From 50 | $45.80 |
Replacement septa are not offered for all cap types and sizes, as manual assembly is not recommendable due to contamination risk and possible wrong side orientation. Nevertheless, for the most common sizes and septa materials we offer them along with the appropriate empty caps. The septa is a molded Butyl/PTFE septa with only centrical PTFE lamination which is why it seals extremely tightly. It has a temperature resistance of -40 °C up to 120 °C.
Nominal diameter | N 20 |
Septa material | Butyl/PTFE (Pharma-Fix) |
Colors of septa material | Dark gray/gray |
Septa thickness | 3.0 mm / 118,1 mil |
Septa hardness | 50° shore A |
Recommended application(s) | Headspace |
Autosampler compatibility | See assembled crimp closures 70234, 70234.10, 702071, 702928.9 |
Storage temperature | 15–25 °C / 59–77 °F |
Scope of delivery | 100x N 20 septa (no cap) |
Gross weight (incl. packaging) | 140 g / 0.31 lbs |
Packaging dimensions | 170 x 120 x 15 mm / 6.69 x 4.72 x 0.59 Inch |
Hazardous material | No |
Extremely tight sealing and excellent analytical purity are of great importance, especially in the headspace area, since high temperatures are often used here causing high internal vial pressure. Since completely PTFE-coated liners have a very slippery surface on the glass rims, the sealing properties can be improved significantly by a PTFE lamination that is only applied centrically in the contact area with the sample.
With these so-called Pharma-Fix septa, the uncoated, elastomeric liner rim is on the vial’s glass crimp neck. As a molded septum, the side edges of these liners are designed lamellar so that they can be well compressed during the crimping process and be firmly pressed onto the glass rim. This creates a kind of suction between the elastomeric material and the edge of the glass, which creates an extremely good and firm seal.
Until now, such special liners were only available as a butyl / PTFE version, which, however, could only be used in a temperature range of -40 °C and 120 °C. Furthermore, butyl is more difficult to penetrate than the much softer silicone and its analytical purity is not as high.
MACHEREY-NAGEL offers two Butyl/PTFE versions in a center hole cap (70234, 70234.10) of which the latter one has a slightly better analytical purity.
Pharma-Fix closures with only centrical PTFE lamination
In addition our delivery program includes a center hole closure with a Silicone/PTFE Pharma-Fix liner (702340), which is characterized by high analytical purity and temperature resistance (-60 °C up to 200 °C) as well as good penetration and excellent sealing properties. The liner is made from the same, well-known blue transparent silicone compound we also use for our completely PTFE laminated closures.